My laptop is set up for a dual boot to Windows and Linux (mint), which what I use 99% of the time. I sent the lap off to the computer manufacture for a warranty repair of the bezel hinge. For some reason, they made an unrequested update to the Bios. I can no longer access Linux, as the computer boots directly to Windows. Linux does not appear in the boot list in the startup. If I boot to linux iso flash drive, I can see my home director but cannot access it. After 10 days, the company has no idea how to fix the problem.

From scanning the internet, I gather that the problem is that access to the grub has been lost. But none of the possibly solutions that I've read seem doable. Many refer to things like "legacy," "ACTH" and other functions that don't appear in the start up. There is reference to a grub repair tool but no clear explanation how to use it you don't have access to your installed Linux. Some fixes seem to require a deep knowledge of Linux I simply don't have and I'm wary in messing around too much in stuff that might destroy what I have on the laptop.

So, I hoping that someone might be able to offer a method for fixing the problem.

Thanks, FA

It is not the BIOS update. I think they repair the Windows bootloader and now you do not have the Grub menu with the options to boot to either system. Reinstalling Grub should solve your problems. Make a backup first.

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When you use the Linux iso you can see your /home directory but not access it. Why not? Can you see the filesystem directories? How did you try to access it and exactly what happened?
Is your Mint install an EFI install or do you know? Which windows version is it, you don't mention that. It could be something as simple as hibernation or Secure Boot turned on by the BIOS update. CHeck those in your BIOS and turn them off to see if it helps.

Try using boot repair at the link below as Mint uses the Ubuntu repositories. Use the 2nd option explained on that page, select to run boot repair with the Create BootInfo Summary option selected. Do not try to make repairs and make thigs worse. Just post the link you get when boot repair finishes here.

https://help.ubuntu.com/community/Boot-Repair

Single hard drive?
Did you boot directly to grub before or did you chain load from windows.
Or did you have two boot loaders?

I disagree - it probably was a firmware update. EUFI uses the NVRAM on the motherboard to hold boot variables - resetting it will purge them. The report requested above should show what's what.

I tried using booting up with the boot-repair disk and predictably, it made things even worse. Now I can't boot into anything.

1. I ran the boot-repair and selected automatic repair
2. I turned off the computer and powered back on. The boot menu listed Ubuntu but not Mint. I selected Ubuntu.
3. It booted up in Mint and everything looked good.
4. When I tried to power down, the computer froze and nothing responded.
5. I shut off the mower manually (holding down the power button)
6. I rebooted again and only got a command prompt: grub>. Huh????
7. If I try to boot off the repair drive again, I still get grub>

What is going on?

Why was the boot option for Ubuntu instead of Mint?
Why did it boot properly on the once?
Why did it freeze when I attempted to shut down?
What am I supposed to do at the grub prompt?

If you know the partition number that linux is on you should be able to bring the grub menu up at the grub prompt with this.

the ? will be the number of the partition that linux is on, and assuming one drive. If it is on a second drive change hd0 to hd1. If you have a boot partition(not esp partition) then it would be and the ? would be the partition number of the boot partition.
If you don't know the partition number the following will help to locate it
change the ? for each partition until you locate the partition with linux files on it.
once booted in run

Thanks for you response. Something isn't working right.

It is a single drive. I examined the partitions with ls(hd0,?)/ where ?=1-6. Partions 1 and 5 both show boot. One starts "EFI" and the 5 starts with "lost+found."

I tried grub>configfile (hd0,1)/boot/grub/grub.cfg and got sent back to the grub> prompt.

When I tied sudo grub-install, I got an "error: can't find command 'sudo'".

I tried the same two commands with grub>configfile (hd0,1) and got the same error.

Which is exactly what I said in my earlier post recommending boot repair, do NOT try to make repairs but create the boot info summary report and post the link here. You created a worse problem from your previous problem. If you are going to go to forums requesting help, it would be a good idea to follow recommendations and if you don't understand suggestions, ask!rum

Always a bad idea. If your keyboard works you can hold down the Ctrl and prtsc buttons simultaneously and type in REISUB to reboot.

EFI installs of Ubuntu drivatives such as Mint usually show ubuntu as the boot option and also usually have an ubuntu directory in the EFI partition.

Basic info you have not posted, which version of windows, which version/release of Mint, UEFI or Legacy install. Also, you were asked several other questions by other members which you did not answer.

You might have had answers from members here to some of your questions if you had simply followed instructions and run boot repair with the Create BootInfo summary option and posted the link here.

Hopefully, you will pay more attention to and follow the suggestions by colorpurple21859. You might have a working system if you do. Good luck.

Several things combined to cause this:

1. Mint is a Ubuntu derivation
2. Mint does not change GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`in the file /etc/default/grub to distinguish it from Ubuntu, which means both depend on the same \EFI\ubuntu directory on the ESP filesystem
3. Because both Mint and Ubuntu depend on #2, the last one to write there wins. Writing there happens:
   • at installation of the distro, or
   • reinstallation of the bootloader

So, Mint must have been the last to write to the \EFI\ubuntu directory.
A web search should turn up several explanations of possibilities, some of which will be similar to colorpurple21859's suggestion. The file /boot/grub/grub.cfg contains a series of commands that the grub shell interprets to produce a menu and load a kernel and initrd. Those very same commands can be typed at a grub> prompt to load Mint's or Ubuntu's kernel and initrd to result in a good boot. Your backups of Mint and Ubuntu contain those grub.cfg files. You could type the commands in the appropriate menu stanza for a normal boot in the Mint version in your backup at the grub> prompt to boot Mint. Or, at least you could have if you hadn't used the boot repair method that you did. The repair may have disturbed the content of \EFI\ubuntu and/or NVRAM with unpredictable results. Maybe you still can, so it's worth trying.

It will be along the lines of or maybe (hd0,5) or (hd0,6), if your not using lvm.

[QUOTE=yancek;6365588]Always a bad idea. If your keyboard works you can hold down the Ctrl and prtsc buttons simultaneously and type in REISUB to reboot.
[/ENDQUOTE]

That doesn't work. If I hold the keys down, I can't type anything. If I type "exit" from grub>, I get booted back into windows and can power down from there. The next power up I'm back at grub>.

I've searched the internet and tried the solutions suggested by page https://www.ubuntubuzz.com/2016/03/b...ub-prompt.html

set root=(hd0,5)
linux /boot/vmlinuz-5.13.0-44-generic root=/dev/sdb5
initrd /boot/initrd.img-5.13.0-44-generic
boot

I got a long string of unreadable output that ended with a phrase that included "panic." I'm guessing that's not good. I can only power off by holding the down the on button.

It would be:
based on your last post.

Possibilities --

1) use a puppy linux to boot and then use Grub4DOS to establish a boot menu allowing either OS to be chosen;
2) Copy any desired files to a USB stick using puppy . . .

before likely reinstalling your desired Linux distro.

3) or purchase EasyBCD for an easy out

I don't understand. When I power up, I immediately get grub>. How do I load a distro from there?